How the Iowa Caucuses Work

February's caucuses will see voters from all of Iowa's nearly 1,700 precincts gather across the state to kick off the first-in-the-nation presidential contest and the first step toward awarding delegates. But the parties differ in how the Feb. 1 results ultimately determine how much support each candidate will have at the national conventions.

Candidate A

Candidate B

Candidate C

Democrats

Caucus goers indicate their candidate preference by standing in certain areas of the room. If a candidate doesn’t reach a certain threshold*, his or her supporters must join a different candidate's group.

This minimum is also required at the later conventions and typically lowers the number of candidates with Iowa delegates at the Democratic National Convention.

Candidate A

Candidate B

Democrats

Candidate A

Candidate B

Candidate A

Candidate B

Democratic delegates aren't required to align with the same presidential preference as they did at any previous stage.

Candidate A

Candidate B

*In most caucuses, Democratic candidates must meet a minimum 15% viability threshold to advance to the next convention.

Precinct Caucuses

Feb. 1

Only registered Republicans and Democrats are eligible to participate, though both parties offer same-day registration.

County Conventions

March 12

In each of Iowa's 99 counties, Republicans and Democrats select delegates to both the state convention and the convention of the congressional district the county is part of.

District Conventions

D: April 30 | R: April 9

Delegates meet in each of Iowa's four congressional districts and elect delegates directly to the national party conventions.

State Conventions

D: June 18 | R : May 2

Both parties choose more delegates to the national convention.

National Convention

D: July 25-28 (Philadelphia) R: July 18-21 (Cleveland)

A different kind of year is raising the prospects of a contested Republican convention, something that hasn’t happened in decades, while Democrats anticipate a more traditional process.

At the Republican event, representatives or surrogates for each candidate give speeches and then attendees vote in presidential preference poll, usually on slips of paper.

Republicans

Candidate A

Candidate B

Republicans

Candidate A

Candidate B

Candidate A

Candidate B

Republican National Convention delegates are bound by the presidential preference results from the precinct caucuses.

Candidate A

Candidate B

Precinct Caucuses

Feb. 1

Only registered Republicans and Democrats are eligible to participate, though both parties offer same-day registration.

Caucus goers indicate their candidate preference by standing in certain areas of the room. If a candidate doesn’t reach a certain threshold*, his or her supporters must join a different candidate's group.

This minimum is also required at the later conventions and typically lowers the number of candidates with Iowa delegates at the Democratic National Convention.

At the Republican event, representatives or surrogates for each candidate give speeches and then attendees vote in presidential preference poll, usually on slips of paper.

County Conventions

March 12

In each of Iowa's 99 counties, Republicans and Democrats select delegates to both the state convention and the convention of the congressional district the county is part of.

District Conventions

D: April 30 | R: April 9

Delegates meet in each of Iowa's four congressional districts and elect delegates directly to the national party conventions.

State Conventions

D: June 18 | R : May 2

Both parties choose more delegates to the national convention. Republican National Convention delegates are bound by the presidential preference results from the precinct caucuses.

National Convention

D: July 25-28 (Philadelphia) R: July 18-21 (Cleveland)

A different kind of year is raising the prospects of a contested Republican convention, something that hasn’t happened in decades, while Democrats anticipate a more traditional process.

*In most caucuses, Democratic candidates must meet a minimum 15% viability threshold to advance to the next convention.